1. Technical Field
The present invention relates to a liquid ejecting head which ejects liquid through nozzle openings and a liquid ejecting apparatus and, particularly, relates to an ink jet type recording head which ejects ink as liquid and an ink jet type recording apparatus.
2. Related Art
A liquid ejecting apparatus represented by an ink jet type recording apparatus, such as an ink jet type printer and a plotter, has a liquid ejecting head which can eject droplets of liquid from a liquid reservoiring unit, such as a cartridge and a tank having liquid reserved therein.
Such a liquid ejecting head includes a pressure generation chamber communicating with nozzle openings through which liquid is ejected and a pressure generation unit which generates changes in pressure in the liquid in the pressure generation chamber and causes liquid droplets to be ejected through the nozzle openings. Examples of a pressure generation unit mounted on a liquid ejecting head include a longitudinal oscillation type piezoelectric actuator, a deflection oscillation type piezoelectric actuator, and an actuator using a heater element or an electrostatic force.
In this case, the liquid ejecting head includes a head main body which ejects liquid and a flow-path member which is provided on a surface side of the head main body, which is the side opposite to a liquid ejection surface side. The liquid is supplied from the flow-path member to the head main body (see, for example, JP-A-2013-176963 or JP-A-2013-176962).
In the case of an ink jet type recording head, when a sealed space is provided in a case body, a problem, such as deformation and a failure in bonding of member, is caused by the expansion/contraction of gas, resulting from changes in temperature. Thus, an atmosphere opening port communicating with the outside is provided in the casing body and the inner portion of the casing body is open to the atmosphere through the atmosphere opening port. In addition, when a solvent-based ink is used, the concentration of volatile components increases in the head, and thus a problem, such as separation in a bonded portion and changes in discharging properties of the head, resulting from changes in elasticity of a film compliance portion, can occur. To prevent this problem, the space in the head is open to the atmosphere.
However, there is a problem in that, when the ink is adhered to the atmosphere opening port, the ink enters an inner portion of the ink jet type recording head through the atmosphere opening port, and thus components in the inner portion of the ink jet type recording head may not function due to the ink.
Such a problem is not limited to an ink jet type recording head and is shared by liquid ejecting heads for ejecting liquid other than ink.